The present invention relates generally to a display device which needs illumination light for a viewer to identify the displayed information under the surroundings being dark such as in nighttime. More specifically, the invention relates to a display device which is capable of providing variety of illumination patterns. The present invention may be embodied widely in various types or kinds of display devices, for example, in automotive vehicle instruments and so forth.
There have been various types of illumination lighting used in display devices, such as those disclosed in Japanese Utility Model First Publications (Jikkaisho) Nos. 59-85910 and 59-85911. Specifically, one type is that an electric filament lamp is provided in a housing in front of a display face member having thereon various information to be indicated by a pointer and illuminates the display face member directly from its front side. Another type is that an electric filament lamp is provided in a housing behind a display face member and light emitted from the lamp is reflected by a reflective member provided forward of the display face member to indirectly illuminate the display face member from its front side. Still another type is that an electric filament lamp is provided in a housing behind a display face member and light emitted from the lamp is transmitted through optically transmittable portions of the display face member, which portions are formed in shapes corresponding to information to be pointed by a pointer, to directly illuminate the information from its back side.
In the conventional display devices as mentioned above, however, the illumination patterns inevitably becomes monotonous since there is only the state of the electric filament lamp being ON or OFF. Though it is important for the display device to display the required information as precise as possible, it has also been getting very important to enhance the visual effects in view of the recent large demand for it.